What Is an NPI Number?

What Is an NPI Number?
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In today’s digital age, encoded data can sometimes cause a snarl on the information highway. Prior to 2004, health care providers used different identifying numbers for themselves when they transmitted health care data online to facilitate patient records among various health plans. Without a standardized system of assigning a single identifying number that each health care provider could use across the board with all its health plans, transmitting data online this way caused lots of digital traffic jams. The introduction of National Provider Identifier (NPI) numbers in 2004 provided this much-needed standard.


  • NPI numbers are unique 10-digit identifiers for health care providers.

National Provider Identifier Numbers

NPI numbers identify each health care provider without providing additional information such as where the provider is located or the type of health care provided. NPI numbers represent the standard health care provider identifying system that the U.S. Department of Health and Human Services (HHS) began using under the Health Insurance Portability and Accountability Act (HIPAA). All HIPAA-covered health care providers as well as those who electronically file claims or digitally bill insurance carriers are required to have an NPI. Although other types of health care providers are not required to have an NPI, they may obtain one if they wish.

Uses for the NPI Number

In addition to its use in HIPAA-related electronic transactions, the HHS identifies other uses for the NPI number:

  • For identifying health care providers on HIPAA-related correspondence.
  • For health care providers to identify themselves in transactions or on correspondence with other health care providers.
  • For health care providers to identify themselves on prescriptions, without replacing the Drug Enforcement Administration’s requirements or a state license number.
  • For health plan administrators to use in their internal provider files in processing transactions and communicating with health care providers.
  • For health plan administrators when coordinating other health plan benefits.
  • For health care clearinghouses to use in their internal files for creating and processing certain transactions and communicating with health care plan providers.
  • By digital patient record systems for identifying health care providers in a patient’s medical records.
  • For HHS in cross-referencing fraudulent health care providers and identifying other compromises to program integrity files.
  • For identifying health care providers in numerous legal pursuits, including the Debt Collection Improvement Act of 1996 and the Balanced Budget Act of 1997.

Who Must Have an NPI?

The HHS defines three types of HIPAA-covered entities: health care providers that make certain electronically transmitted transactions, health care clearinghouses and health plans such as Medicare, Medicaid and commercial plans. Even HIPAA-covered health care providers who do not electronically transmit their own data must have an NPI number (for example, these providers task a business associate to do this).

HHS further defines two categories of health care providers, which are HIPAA-covered entities, that must have an NPI – individuals (Entity Type 1) and organizations (Entity Type 2).

  • Entity Type 1 – individual health care providers. This category also includes sole proprietors, who must apply for their NPI by using their Social Security number (SSN) instead of an employer identification number (EIN). Examples include physicians, dentists, nurses, chiropractors, physical therapists and pharmacists.
  • Entity Type 2 – organization health care providers. An organization may be comprised of only one employee, such as an incorporated individual, or thousands of employees. Examples include group practices, clinics, hospitals, pharmacies, nursing homes, health maintenance organizations (HMOs), home health agencies (HHA) and residential treatment centers.

Obtaining an NPI Number

HIPAA-covered entities, whether they’re individuals or organizations, must apply for their NPIs through the Centers for Medicare and Medicaid Services (CMS) National Plan and Provider Enumeration System (NPPES). After an entity receives its NPI, the HHS publishes the health care provider’s name, address and specialty under its NPI number, in accordance with federal law.